Coatings may be applied to components of a machine to reduce wear and/or prevent corrosion. For example, where opposing components contact one another, and one moves relative to the other, a coating may be applied to the component surfaces to reduce wear between the components by controlling friction and/or providing increased resistance to wear. Nanoparticulate based materials, or ultra-fine grains and particles, can be added to the coatings to improve surface properties of the coating.
One application of a nanoparticle based coating is described in U.S. Pat. No. 7,097,922 B2 (the '922 patent) to Shen et al., issued on Aug. 29, 2006. The '922 patent describes a multi-layer super-hard nanocomposite coating for coating contact surfaces on substrates in a variety of industrial processes. A superficial layer of the super-hard nanocomposite coating includes a titanium-silicon-nitrogen (Ti—Si—N) film with microstructures having nanocrystalline grains of titanium nitride (TiN) in an amorphous matrix of silicon nitride (SiN). The nanocrystalline TiN may help to hinder the propagation of nanocracks and reinforce the bonding of grains and grain boundaries of the coating.
Although the nanoparticle based coating of the '922 patent may provide improved surface properties, it may have limitations. For example, the surface chemical reactivity of the particles of nanometer dimensions may be high. Therefore, the discrete nanocrystalline grains of the '922 patent may have a tendency to bind together (agglomerate). Additionally, because the TiN nanocrystalline grains are within an amorphous matrix of SiN, the nanocrystalline grains may fail to provide lubricating properties for the coating.
The coating of the present disclosure is directed towards improvements to the existing technology.